This is the second submission of a proposed study designed to investigate possible mechanisms leading to enhanced weight gain in premature infants who receive massage. Multiple investigations demonstrated that preterm neonates who received massage therapy for five to ten days exhibited 28 to 47 percent greater daily weight gain. Findings were consistent in showing that preterms receiving massage do not consume more formula or calories than control infants. The proposed research will examine possible underlying mechanisms for this enhanced weight gain following massage therapy. The model that will be tested is that moderate pressure massage therapy enhances vagal activity, which in turn promotes gastric motility and the release of hormones that enhance the metabolism of digestion. Medically-stable preterm neonates (N=120) residing in the progressive or intermediate care nurseries will be matched on gestational age, birthweight, NICU days, mother's SES, and entry weight and then assigned to one of three groups: Massage Therapy (n=40), Sham Massage (n=40), or Control (n=40). Massage therapy and Sham Massage will be provided for 15 minutes, three times per day, for five days. Massage Therapy will use moderate pressure and Sham Massage will use light pressure. Group comparisons will focus on physiologic (vagal tone and gastric motility), biochemical (serum insulin, IGF-I, oxytocin, and cortisol) and behavioral (performance on the Brazelton Neonatal Behavior Assessment Scale) variables. At the end of the 5-day period, the massaged infants are expected to show: 1) higher vagal tone during massage and higher vagal tone across the study; 2) higher concentrations of serum insulin, IGF-I, and oxytocin, and lower cortisol; 3) greater gastric motility values, and 4) superior performance on the Brazelton. Regression analyses will be conducted to determine the percentage of variance in weight gain and Brazelton performance that is accounted for by the physiologic and biochemical variables.